Aileron control



Patented Sept. 1 1936 UNETED STATES PATENT OFFICE AILERON CONTROL Leonard 0. Cederwall, Kenmore, N. Y., assignor to Curtiss Aeroplane & Motor Company, Inc., a corporation of New York Application May 11, 1934, Serial No. 725,140

8 Claims. (Cl. 244-29) This invention relates to aircraft control sysing the specification and in examining the draw- ,tems, and is particularly concerned with improveing, in which:

inents in operating mechanisms forailerons. Fig. 1 is a plan of a portion of a wing and Inconventional aileron control systems, whereaileron, partly broken away; in the ailerons are mounted toward the outer ends Fig. 2 is a section through the wing and aileron, 5 of the main wings, cables are sometimes used, showing the aileron operating mechanism; and

running over pulleys, to transmit motion of the Fig. 3 is a section similar to Fig. 2, showingv a control stick to the ailerons. Also, push-pull rods different arrangement of certain of the operating are sometimes used to connect the stick will bell mechanism elements.

cranks near the ailerons, which bell cranks, in A wing 5 includes the usual wing spar 6, from 10 turn, are connected to the ailerons. The latter which a bracket I extends rearwardly to a point construction lends itself to differential aileron near to the wing trailing edge, the bracket carryaction whereby the aileron moves upwardly to a in a a l n 8 on a hinge 9- As s w l n wn greater extent than it moves down, but a pluralin the art, a plurality of such brackets and hinges it of bearings, pivots and' the like are necessary are spac d al n th win t support the aileron 15 to accomplish the intended result. All these at a p u y o p ese hinges are so arpivots and bearings give an opportunity for play ranged that the aileron may swing upwardly or and lost motion which is most objectionable, and downwardly ab t t e hinge to e e t te l consuch construction does not inherently lend itself trol- One more ailerons e Organized a ch to extrem li ht weight side of the plane of symmetry of the aircraft and 20 This invention consists generally i pushare arranged so that the ailerons on one side move pull tube within the wing, moved under the in- 1 While those 011 the pp Side o e d fluence of the control stick, and guided for axial and vice versa- The aileron 8 ud s a spar 0 translation by suitable rollers. The aileron, unt d n the hinges 9. sa d spa forming t hinged to the wing trailing edge, is provided with main Structural element of the aileron, d a 25 the usual horn or operating lever, the horn being hem level is mounted 011 said p the nd directly connected by a diagonal push-pull memof the horn being spaced from the axis of the her to the push-pull tube. In all positions of hinge 9, whereby forward or rearward movement aileron adjustment, the diagonal member makes of the upper end of the horn may move the aileron an acute angle with the push-pull tube. By upWaldly dow y- 0 pushing or pulling said tube, the diagonal mem- 2 Shows the hinge 9 near the bottom bers angle thereto is changed, and, since the face of the aileron, With the upper d of the length of the member is constant, the aileron horn H Within the confines theI'eOf, 50 that 110 horn must necessarily move toward or away from Projections te O the am- 3 th t b ,thu raising Qrlgwering t 11 If shows an alternative construction wherein the 5 in the neutral aileron position-the diagonal memhinge '9 s located adjacent the pp r Su ber makesan angle of about 70 with the tube, of h ai the h ll projectin abov said when the angle is increased by sliding the tube, pp S a ethe aileron is moved only a small amount; con- Within the W 5 d attac ed to the real- 40 versely, when the angle is decreased, the aileron is Ward face of the p r 6, are a plu y f guides 40 k moved a relatively large amount. This allows of Withih which a hushfpull tube 15 automaticdifierential operation of the aileronsranged to m du'ectlon Parallel to the the decrement in' the angle mentioned is applied wmg Span smtable means Well known in the raisin the He art are provided at the inner end of the pushinloweflgng'thz igi i the mcrementis apphed pull tube I3 for controlled movement thereof. 45

Objects of the invention are to provide a simple 2 5 3 3 13 if g zai i g 1 3: Z 35 operating mechanism for aircraft control sur- 1y through the guides with a minimum of faces; to provide a mechanism free from'a large tion The tube H and the m H are joi ed number of Pivots and hinge joints; to Provide a by a link I5, said link having a pivotal con- 50 mechanism which by its inherent design may be necnon with t t [3, and having mmade light in W a d to P v de a p versal ballconnection I! with the upper end of light weight mechanism for effecting differential the horn I I. This link I5 is of such a length aileron control. that, when the aileron is in its neutral posi- Further objects will become apparent in readtion as shown in solid lines, the link will make 65 an acute angle with the tube It, said angle being on the order of about 70. When the tube I3 is drawn inwardly, the angle between the link l and the tube will be increased, since the joint I! may not move laterally. Thereby, the projected length of the link I5 on a line normal to the tube l3 and intersecting the joint I! must increase, whereupon the aileron is swung downwardly about the hinge 9. Conversely, when the tube I 3 is pushed outwardly, the angle between the link l5 and the tube i3 is decreased, causing the aileron to be pulled to an upward position. In Figs. 1 and 2, the dot and dash lines represent the position of the link l5 and aileron when the aileron is depressed. The dotted lines in Figs. 1 and 2 represent the link and aileron, respectively, when moved to an up position. It will be seen that the link IS in any position of adjustment, always makes an acute angle with the tube l3, and no dead center position may be reached. This organization inherently causes the aileron to have an upward angular movement greater than the downward angular movement thereof, each from the neutral position, even though the translational movement of the tube l3 may be equal from the neutral position. This,

-of course, is due to the fact that the projection of the link l5 on a line normal to the tube I 3 varies in a non-uniform manner with translational movement of the tube l3. Inherently, then, differential action of the aileron accures, which is most desirable. In the prior art, many more complicated mechanisms have been used to attain this differential action, whereas in this embodiment, such action is automatically attained by the extremely simple organization of the aileron actuating mechanism. Obviously, when the tube I3 is connected with a similar tube on the opposite side of the aircraft, through the medium of a suitable control stick, opposite movement of the ailerons is attained when the control stick is moved. The degree of differential action of the aileron above the neutral plane and below the neutral plane may be easily determined by the location of the link pivot l6. In order to provide for adjustment of aileron position, the link l5 may be constructed with a screw connection l8 similar to a turnbuckle. Slots I9 and 20 of suitable conformation are formed in the trailing edge of the wing and the leading edge of the aileron, respectively, so that the link 15 may have a free path of movement through the airfoil surfaces.

When the control system of this invention is used for aileron control, the link l5 should preferably make less than a right angle with the push-pull tube I3 in all positions, to avoid dead centers. When the system is used. as it may readily be, for the actuation of lift increasing wing flaps, the link l5 might preferably be arranged to move past a right angled position relative to the push-pull tube. Thereby, the flap would be irreversibly locked in the down attitude until control effect is exerted on the tube l3.

While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifications and changes.

What is claimed is:

1. Control means for an aileron transversely hinged to the trailing edge of a wing including a push-pull rod extending laterally within the wing, a push-pull member pivoted to said rod and extending rearwardly therefrom, a horn spaced from the aileron hinge axis, and pivot connection between said horn and the rearwardlend of said member.

2. In an aileron control mechanism for an aileron hinged to a wing, an aileron horn having a terminal spaced from the hinge axis, a pushpull control rod substantially parallel to the aileron hinge axis and forwardly spaced therefrom, and a single push-pull member pivoted to said push-pull rod and to said horn terminal.

3. In an aileron control mechanism for an aileron hinged to a wing, an aileron horn having a terminal spaced from the hinge axis, a push-pull control rod substantially parallel to the aileron hinge axis and forwardly spaced therefrom, and a single push-pull member pivoted to said pushpull rod and to said horn terminal, said member in all positions of adjustment making an acute angle with the axis of said rod.

4. In a control system, a wing, a push-pull rod axially movable therein, guide means for constraining said rod to axial movement, a flap hinged to said wing, a pivot carried by said flap, said pivot being spaced from the flap hinge axis, and a single push-pull member pivoted at its ends to said rod and to said flap pivot and making at all times an acute angle with said rod axis and with the plane of the locus of said flap pivot.

5. In an aircraft control system including an axially translatable control rod and an element movable along a line substantially normal to the line of said rod movement, means for moving said element in response to movement of said rod comprising a single push-pull member pivoted at its ends to said rod and to said element and making an acute angle with said rod axis and with th plane of movement of said element.

6. In an aircraft control system including an axially translatable control rod and an element a s, means for moving said lever about its ful crum in response to axial movement of said rod comprising a connecting member pivoted to both said lever and to said rod, said member, throughout the normal range of movement of said system, making acute angles of varying degree with said rod axis.

8. In a control system including a flap hinged to a wing, a control rod axially movable within said wing, said flap being hinged to said wing on a hingeaxis spaced from and substantially parallel to said rod, a ball pivot carried by said flap in spaced relation above said hinge axis, and a push-pull member pivoted at one end to said rod and havinga length somewhat greater than the minimum distance betweensaid rod and said ball pivot, said member having a socket at its opposite end engaging said ball pivot, whereby movement of said rod translates the corresponding end of said member to effect movement of said ball pivot about said flap hinge axis.

LEONARD O. CEDERWALL. 76 

